A conventional pressure switch is disclosed in Japanese Utility Model Laid-Open No. 166,939/1985 and shown in FIG. 4, where the pressure switch is generally indicated by numeral 7. This switch 7 comprises an insulator 1 and a body 5. One fringe of the body 5 is totally crimped against the insulator 1 so that the body 5 is rigidly fixed to the insulator 1. A fixed contact 6 is mounted in the body 5 that is made of a metal. The fixed contact 6 is electrically and mechanically connected with the body 5.
The insulator 1 is made of an insulating material. A terminal 2 that is connected with a movable contact 9 has its one end portion crimped against the insulator 1. The terminal 2 is electrically connected with the movable contact 9 via a connecting plate 8 and a spring 9a. A porous filter 3 and a presser member 4 for pressing the filter 3 against the insulator 1 are interposed between the insulator 1 and the metallic terminal 2. This terminal 2 is crimped against the insulator 1.
When this pressure switch is assembled, if the terminal 2 is not sufficiently crimped, then the porous filter 3 cannot be sufficiently pressed against the insulator 1, creating a gap between the filter 3 and the insulator 1. If water or dust enters through this gap, the characteristics of the pressure switch may be impaired. For this reason, the components must be sized sufficiently accurately. Also, the crimping operations must be performed carefully. Therefore, much labor and a special crimping machine are required. As a result, the switch is manufactured inefficiently and expensively.